This is a schematic of the photocatalytic nanocrystal. Credit: Journal of Visualized Experiments

One
reason that solar energy has not been widely adopted is because light
absorbing materials are not durable. Materials that harvest solar
radiation for energy often overheat or degrade over time; this reduces
their viability to compete with other renewable energy sources like wind
or hydroelectric generators. A new video protocol addresses these
issues by presenting a synthesis of two inorganic nanocrystals, each of
which is more durable than their organic counterparts.

The article, published in Journal of Visualized Experiments (JoVE), focuses
on the liquid phase synthesis of two nanocrystals that produce hydrogen
gas or an electric charge when exposed to light. “The main advantage of
this technique is that it allows for direct, all inorganic coupling of
the light absorber and the catalyst,” says the leading author Dr.
Mikhail Zamkov of Bowling Green State University.

Zamkov’s
nanocrystals are unique for two reasons: they separate charge in
different ways due to their architectures, and they are inorganic and
durable. The first nanocrystal is rod-shaped, which allows the charge
separation needed to produce hydrogen gas, a reaction known as
photocatalysis. The second nanocrystal is composed of stacked layers and
generates electricity, thus being photovoltaic. Because the
nanocrystals are inorganic, they are easier to recharge and less
sensitive to heat than their organic counterparts. Zamkov’s inorganic
photocatalytic material allows a rechargeable reaction when exposed to
cheap organic solvents, whereas in traditional photocatalytic reactions
the catalyst is often irreversibly degraded. The photovoltaic
nanocrystals can also withstand higher heat than the traditional
photovoltaic cells that do not dissipate heat well.

“We
have established a new method for making photocatalytic and
photovoltaic materials. This is important primarily as a new strategy
for making photovoltaic films that are 100% inorganic, thus producing a
more stable solar panel. It is a design that you could reach
marketability,” Zamkov says. “It is important to have these steps
documented in a video format, as the synthesis of the photocatalytic
nanocrystals and the photovoltaic cells are long procedures with
detailed steps. It makes our technique more visible and accessible.”

Source: JOVE